Determination of oxidation products in transformer oils using FT-IR spectroscopy

Transformer oils are subject to a lot of control checks in the process of their exploitation, because the presence of oxidized products causes damages in the electrical equipment. In the process of exploitation of transformer oils anti-oxidation additives get exhausted and products of oxidation are formed. This paper describes the development method for study of oxidation transformer oils by Fourier transform infrared (FT-IR) spectroscopy. The aim of this paper is to determine the main products of oxidation of transformer oils and to increase the sensitivity of FT-IR analysis by the extraction method. The method which we suggest to register all oxidized products is of great interest. The problem is the detection limit of routine apparatus. For this reason we have developed an extraction method, which can identify precisely all oxidized products qualitatively and quantitatively in the region 1800-1650 cm⁻¹. Thus a manifold increase of the FT-IR analysis is achieved, combined with increased sensitivity, precision and the possibilities for registering micro-amounts otherwise beyond the routine technique. FT-IR spectroscopy is a powerful method with great practical significance for investigation of carbonyl- and carboxylic degradation products from transformer oils.